MC68HC708XL36 FREESCALE [Freescale Semiconductor, Inc], MC68HC708XL36 Datasheet - Page 307

• Manufacturer Part Number: MC68HC708XL36
• Description: HCMOS Microcontroller Unit
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

I/O Signals
CGMXCLK
STOP Instruction
COPCTL Write
Power-On Reset
3-copopt2_b
MOTOROLA
NOTE:
NOTE:
Service the COP immediately after reset and before entering or after
exiting stop mode to guarantee the maximum time before the first COP
counter overflow.
A COP reset pulls the RST pin low for 32 CGMXCLK cycles and sets the
COP bit in the reset status register (RSR).
In monitor mode, the COP is disabled if the RST pin or the IRQ pin is
held at V
disables the COP.
Place COP clearing instructions in the main program and not in an
interrupt subroutine. Such an interrupt subroutine could keep the COP
from generating a reset even while the main program is not working
properly.
The following paragraphs describe the signals shown in
CGMXCLK is the crystal oscillator output signal. CGMXCLK frequency
is equal to the crystal frequency.
The STOP instruction clears the COP prescaler.
Writing any value to the COP control register (COPCTL) (see
Control Register
stages 12 through 5 of the COP prescaler. Reading the COP control
register returns the reset vector.
The power-on reset (POR) circuit clears the COP prescaler 4096
CGMXCLK cycles after power-up.
Freescale Semiconductor, Inc.
For More Information On This Product,
DD
+ V
Go to: www.freescale.com
Hi
. During the break state, V
on page 308) clears the COP counter and clears
COP
DD
+ V
Hi
on the RST pin
MC68HC708XL36
Figure
COP
I/O Signals
1.
COP
307